Diabetic vasculopathy in the rat: an in vivo microscopic study of the circulation

A transparent tissue chamber adapted to the rat back was used for in vivo observation of vascular and circulatory changes in the streptozotocin diabetic rat. The chamber was implanted in a functional and richly vascularized bed of striated muscle. Extensive red cell rouleaux formation was observed within 2-7 days of induction of hyperglycaemia and was closely followed by development of constrictions and dilatations in both venules and arterioles. In 3 of 7 diabetic rats saccular microaneurysms, similar in form to those reported in diabetic animals and humans, developed in the vascular bed. The rat back chamber provides an opportunity for continuous in vivo study of vascular lesions developing in streptozotocin diabetes. Fixation under microscopic observation allows close correlation of functional changes in vivo with the ultrastructural appearance of specific tissue areas.